ej6sir-t

iTrader: (1)

Looking for opinions with reasons for transmission selection for my GSR with gt3582r turbo, power will be around 375/550 based on pump/race and dont tell me to search i tried its just as easy for you to answer. preferrably a tranny with a lsd, I will be probably be purchasing a brand new one from honda/acura so it has to be from a usdm model what should i choose and why GSR, Type R, or is a JDM option from a civic or something better?

TheShodan

iTrader: (14)

That type of LSD (Torsen) from the OEM is not going to help with that kind of power. IF you have transmission already, save the money from new from the dealership and get something is going to work with the type of driving you plan to do. The reason why the OEM LSD is not optimal is because it does not engage the secondary part of the differential until the wheels are turned. In other words, it will almost act like an open differential until either the wheels are turned, or the torque steer allows the wheel to turn, in which only THEN will the LSD activates. If you want one that is much more able to handle the abuse of your GT3582R build, use a Helical LSD such as a Quaife, MFactory, or WaveTrac Limited Slip.

If you plan to circuit race the car, or something to that effect (AutoX or even Time Attack), then you need a mechanical CLUTCH-type LSD, such as Cusco, Kaaz, or the MFactory Clutch-type.

Here are the differences you can read up on. You don't want a Detroit Gear Locker or "spool" in this case

http://en.wikipedia.org/wiki/Limited_Slip_Differential


As for your Transmission choice
A GS-R transmission with a GS-R Engine is optimal, because it can keeps its acceleration rate due the 4.4 final drive already in the car, and there is no need to downshift 2 gears to get any type of powerband as with the LS. (Don't fall for the myth that LS "keeps you in boost longer". YEs you hear the turbo spooling up, but you're not really going anywhere...Especially in a GT3582R.

Here is the transmission Gearing chart on the Major B-series engines. I strongly suggest keep your GS-R and put the money towards a proper limited slip differential and not worry about the "JDM" versions of the transmissions for this type of engine build.



I think I've given more than enough info for you to go on to start here. ;-) Good Luck.

prsxr88

such an imformative post^^^

nealnanoHX

GSR or LS trans with a good LSD as Shodan said. IME B16 and ITR trans are just to short for boost.

blackeg

If you are going to be drag racing the car, then you can calculate transmission from the mph based on your power and tire size. You want to work it so that you pass through the traps as high up in 4th as you can. With your setup it seems like a gsr tranny with some 24.5" slicks is the best bet, putting you at the ebd of the 1/4 mile in the mid 8000rpm range.

I make similar power to u, (a little more on pump, less on racegas) and am using a gsr trans with mfactory lsd. It kinda is a little crappy cruising at 75-80mph, but is great for matching my engine's powerband.

Don't get an ls tranny, mathmatically its not accelerating as much as a vtec trans. U can use a b16 for the track but I think you will likely have to spin the engine low 9000 rpm range. Whatever you pick, a good aftermarket lsd is pretty much a requirement

TheShodan

iTrader: (14)

LS is HORRIBLE without some sort of additional final drive. B16/ITR are great for street/ time attack, and all around. As for what's best for drag racing strictly...... ask someone else, because that's not my area of experience. ;-)

ej6sir-t

iTrader: (1)

Shodan, thank you for detailed answer. Sadly I have an LS. I will be searching for GSR, and an LSD for it. I am still a little confused though. Are you saying the OEM unit, which is a Helical type (according to Acura) is inferior because it cannot handle the power? Or...?

TheShodan

iTrader: (14)

It's not about handling the power. I'm saying that it won't work effectively in the way you think it will because 1) it is over 2.5 times the power that the OEM could be effective for, causing a lot of torque steer, 2) it will act like an open differential until you turn a corner, 3) it will cause a large amount of torque steer in the opposite direction with an equal amount of force as what it first experiences. this means you need another TYPE of LSD.

Also, don't fret about the LS transmission. that is an easy fix without having to sell what you have and buy another one, or swap out a lot of mix-matched gears. for over 300-500whp, the only thing the LS transmission needed to be effective was a change in final drive.

In your case, you don't need to change any actual gears themselves, because the shorter final drive (I highly recommend the MFactory 4.785 Final drive designed for B16/LS transmissions) actively shortens the other gears down at the same time acting as a torque multiplier (not actual torque but added torque in the powerband as you go through the gears) and simply use that.

for my Time Attack car, I had an older LS transmission as my original GS-R was given to my brother. after going through about 4-6 gear set change ups, the best method wound up being the simple; 4.785 final drive, and ultimate a GS-R 3rd gear (because of the circuit tracks I ran sort of needed it), and that's it.

So, cliffs:

1. No, your OEM LSD will not work the way you think it will. It won't break, necessarily, but will not work properly either. It's time for Helical from Quaife, Wavetrac or MFactory

2. Its ok to have an LS transmission, all you need to do is purchase a shorter final drive

3. I recommend the MFactory 4.785 final drive made for the b16/LS transmission as they have the correct bolt pattern without having to modify it for a OEM JDM 4.785 FD.

ej6sir-t

iTrader: (1)

Ok I just thought that quaife was helical just like oem, but i guess it is a different design. Thank you for answer again, I will reaserch how to swap transmission components.

TheShodan

iTrader: (14)

OEM is Torsen, not helical. Check that LSD link I gave you for the various types

ej6sir-t

iTrader: (1)

this says its helical: http://www.acuraautomotiveparts.org/...s=&view=normal

My helms manual says its helical as well as mys Acura type r technical guide

TheShodan

iTrader: (14)

Sorry. My apologies. I didn't see you wrote own and helical. I retract my statement

ej6sir-t

iTrader: (1)

type r technical guide

ej6sir-t

iTrader: (1)

Yes OEM is helical.

ej6sir-t

iTrader: (1)

So the OEM helical will not cause problems?

TheShodan

iTrader: (14)

GRRR.. Even though it is helical.. look at my 3 reason why it won't work well in the cliff notes. Its not worth buying a whole new transmission. Quaife, Wavetrac, MFactory...

TRUST ME..

ej6sir-t

iTrader: (1)

Haha ok, thanks for not getting mad. Any body else out there have an opinion on OEM LSD differential?

ej6sir-t

iTrader: (1)

Shodan what you have been trying to say is that the OEM LSD is a Torsen unit which is a type of Helical LSD am I correct?

TheShodan

iTrader: (14)

Yes. that is correct. The helical /torsen is a gear-type LSD

ej6sir-t

iTrader: (1)

Ok glad we are on the same page . Ok I am debating keeping the LS with the lower FD and added LSD but... the LS will still have the same gear spread, wont this cause the tranny to still be less advantageous than the GSR?

nealnanoHX

Agreed for street driving and time attack ITR or B16 is the better choice as the LS is to long for that type of driving. The LS trans would keep you out of the power band after shifting. I was thinking for drag racing the LS is a better choice because the longer gears keep you in boost longer for the straight run, plus if running from 15-11's ET you trap in 4th gear. Less shifting= more time in boost and in power. The GSR with a good LSD is the best compromise middle ground trans.

trunkluv

what about b16 trans b16 gears with mfactory lsd and ls final drive?

TheShodan

iTrader: (14)

I keep saying this over and over again. 1) being "in boost longer" doesn't mean anything with this kind of gearing because YOU ARE NOT ACCELERATING ANY FASTER than with a GS-R transmission ( unless you use a shorter final drive).. That does not work.

If you keep the LS transmission, please change your final drive as it affects ALL of the gears in a positive way. Yes. Even in drag racing

TheShodan

iTrader: (14)

No. It will drop you out of the power and completely as you go from 4th to 5th gear. It will bog you down as though you are pulling a trailer.

TheShodan

iTrader: (14)

It will NOT have the same gear spread with this combination. In fact you will make the car even less responsive. Start understanding what a final drive truly does